JSON处理工具

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Jackson JSON处理工具类

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jackson jar包依赖

<dependency>      <groupId>org.codehaus.jackson</groupId>      <artifactId>jackson-mapper-asl</artifactId>      <version>1.9.6</version> </dependency>

import java.io.IOException;import java.text.SimpleDateFormat;import org.apache.commons.lang.StringUtils;import org.codehaus.jackson.JsonParser;import org.codehaus.jackson.map.DeserializationConfig;import org.codehaus.jackson.map.ObjectMapper;import org.codehaus.jackson.map.annotate.JsonSerialize.Inclusion;import org.codehaus.jackson.type.TypeReference;import org.slf4j.Logger;import org.slf4j.LoggerFactory;/** * Jackson JSON处理工具类 * @author taiyang * @date 2016-05-05 */public class JsonMapper {private static final Logger logger = LoggerFactory.getLogger(JsonMapper.class);private ObjectMapper mapper;public JsonMapper(Inclusion inclusion) {mapper = new ObjectMapper();//允许json格式是单引号mapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);//设置输出包含的属性        mapper.setSerializationInclusion(inclusion);//设置输入时忽略JSON字符串中存在而Java对象实际没有的属性mapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);//禁止使用int代表Enum的order()來反序列化Enum,非常危險mapper.configure(DeserializationConfig.Feature.FAIL_ON_NUMBERS_FOR_ENUMS, true);}/** * 创建输出全部属性到Json字符串的Binder. */public static JsonMapper buildNormalBinder() {return new JsonMapper(Inclusion.ALWAYS);}/** * 创建只输出非空属性到Json字符串的Binder. */                     public static JsonMapper buildNonNullBinder() {return new JsonMapper(Inclusion.NON_NULL);}/** * 创建只输出初始值被改变的属性到Json字符串的Binder. */public static JsonMapper buildNonDefaultBinder() {return new JsonMapper(Inclusion.NON_DEFAULT);}//===========================================================/** * Obj 2 Json */public String Obj2Json(Object object) {try {return mapper.writeValueAsString(object);} catch (IOException e) {logger.error("Obj2Json error:{}--{}", object, e);return null;}}/** * Json 2 Entity */public <T> T Json2Entity(String jsonString, Class<T> clazz) {if(StringUtils.isEmpty(jsonString)) {return null;}try {return mapper.readValue(jsonString, clazz);} catch (IOException e) {logger.error("Json2Entity error:{}--{}", jsonString, e);return null;}}/** * Json 2 Collection(Map) * 读取集合如List/Map * List<MyBean> beanList = binder.getMapper().readValue(listString, new TypeReference<List<MyBean>>(){}); */    public <T> T Json2Collection(String jsonString, TypeReference<T> typeReference) {        if (StringUtils.isEmpty(jsonString)) {            return null;        }        try {            return mapper.readValue(jsonString, typeReference);        } catch (Exception e) {        logger.error("Json2Collection error:{}--{}", jsonString, e);            return null;        }    }        /** * 设置转换日期类型的format pattern,如果不设置默认打印Timestamp毫秒数. */public void setDateFormat(String pattern) {if (StringUtils.isNotBlank(pattern)) {SimpleDateFormat df = new SimpleDateFormat(pattern);mapper.getSerializationConfig().withDateFormat(df);mapper.getDeserializationConfig().withDateFormat(df);mapper.setDateFormat(df);}}}

import java.util.ArrayList;import java.util.List;import org.codehaus.jackson.type.TypeReference;import org.json.JSONException;import org.json.JSONObject;/** * 测试json */public class TestJson {public static void main(String[] args) throws JSONException {    JsonMapper jm = JsonMapper.buildNormalBinder();            //1.Obj2Json    String jsonStr = jm.Obj2Json(new User());        System.out.println(jsonStr);        System.out.println("========================");                //2.Json2Entity        User user = jm.Json2Entity(jsonStr, User.class);        System.out.println(user.getName() + "-" +user.getAge());        System.out.println("========================");                //3.Json2Collection        User user1 = new User();        User user2 = new User();        List<User> userList = new ArrayList<User>();        userList.add(user1);        userList.add(user2);        String jsonUserList = jm.Obj2Json(userList);        List<User> userListJ = jm.Json2Collection(jsonUserList, new TypeReference<List<User>>(){});        for(User u : userListJ){        System.out.println(u.getName());        }        System.out.println("========================");                JSONObject jsonobj = new JSONObject(jsonStr);        String name = jsonobj.getString("name");        System.out.println(name);}static class User {int id = 1; String name = "taiyang";int age = 26;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}}}

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